diff --git a/MANIFEST.in b/MANIFEST.in
index 6d1198817..b4bfa7b81 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,2 +1,4 @@
+global-exclude *.class *.pyc *.pyo *.so *.dll __pycache__
 recursive-include neo4j *.c
-recursive-exclude test *
+recursive-include neo4j *.pyx
+prune test
diff --git a/neo4j/addressing.py b/neo4j/addressing.py
index c70b2d85f..8dca01e17 100644
--- a/neo4j/addressing.py
+++ b/neo4j/addressing.py
@@ -20,13 +20,34 @@
 
 
 from collections import namedtuple
-from socket import getaddrinfo, gaierror, error as SocketError, \
-    SOCK_STREAM, IPPROTO_TCP, AF_INET6, inet_aton, inet_pton
+from socket import getaddrinfo, gaierror, SOCK_STREAM, IPPROTO_TCP
 
 from neo4j.compat import urlparse
 from neo4j.exceptions import AddressError
 
 
+VALID_IPv4_SEGMENTS = [str(i).encode("latin1") for i in range(0x100)]
+VALID_IPv6_SEGMENT_CHARS = b"0123456789abcdef"
+
+
+def is_ipv4_address(string):
+    if not isinstance(string, bytes):
+        string = str(string).encode("latin1")
+    segments = string.split(b".")
+    return len(segments) == 4 and all(segment in VALID_IPv4_SEGMENTS for segment in segments)
+
+
+def is_ipv6_address(string):
+    if not isinstance(string, bytes):
+        string = str(string).encode("latin1")
+    segments = string.lower().split(b":")
+    return 3 <= len(segments) <= 8 and all(all(c in VALID_IPv6_SEGMENT_CHARS for c in segment) for segment in segments)
+
+
+def is_ip_address(string):
+    return is_ipv4_address(string) or is_ipv6_address(string)
+
+
 IPv4SocketAddress = namedtuple("Address", ["host", "port"])
 IPv6SocketAddress = namedtuple("Address", ["host", "port", "flow_info", "scope_id"])
 
@@ -65,25 +86,3 @@ def resolve(socket_address):
                 getaddrinfo(socket_address[0], socket_address[1], 0, SOCK_STREAM, IPPROTO_TCP)]
     except gaierror:
         raise AddressError("Cannot resolve address {!r}".format(socket_address[0]))
-
-
-def is_ipv4_address(string):
-    try:
-        inet_aton(string)
-    except (OSError, SocketError):
-        return False
-    else:
-        return True
-
-
-def is_ipv6_address(string):
-    try:
-        inet_pton(AF_INET6, string)
-    except (OSError, SocketError):
-        return False
-    else:
-        return True
-
-
-def is_ip_address(string):
-    return is_ipv4_address(string) or is_ipv6_address(string)
diff --git a/neo4j/meta.py b/neo4j/meta.py
index 9ed76aa83..3086cb71b 100644
--- a/neo4j/meta.py
+++ b/neo4j/meta.py
@@ -19,4 +19,4 @@
 # limitations under the License.
 
 
-version = "1.2.0rc1"
+version = "1.2.0rc2"
diff --git a/setup.py b/setup.py
index 171bdc31f..641ff9c3f 100644
--- a/setup.py
+++ b/setup.py
@@ -18,7 +18,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
+
+from __future__ import print_function
+
+from os.path import dirname, join as path_join
 try:
     from setuptools import setup, Extension
 except ImportError:
@@ -30,41 +33,54 @@
     from Cython.Build import cythonize
     from Cython.Distutils import build_ext
 except ImportError:
-    cmdclass = {}
     ext_modules = [
         Extension("neo4j.bolt._io", ["neo4j/bolt/_io.c"]),
         Extension("neo4j.packstream._packer", ["neo4j/packstream/_packer.c"]),
         Extension("neo4j.packstream._unpacker", ["neo4j/packstream/_unpacker.c"]),
     ]
 else:
-    cmdclass = {'build_ext': build_ext}
     ext_modules = cythonize([Extension("*", ["**/*.pyx"])])
 
+classifiers = [
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: Apache Software License",
+    "Operating System :: OS Independent",
+    "Topic :: Database",
+    "Topic :: Software Development",
+    "Programming Language :: Python :: 2.7",
+    "Programming Language :: Python :: 3.4",
+    "Programming Language :: Python :: 3.5",
+    "Programming Language :: Python :: 3.6",
+]
+packages = [
+    "neo4j",
+    "neo4j.bolt",
+    "neo4j.compat",
+    "neo4j.packstream",
+    "neo4j.v1",
+]
+package_data = {
+    "neo4j.bolt": ["*.pyx"],
+    "neo4j.packstream": ["*.pyx"],
+}
+setup_args = {
+    "name": "neo4j-driver",
+    "version": version,
+    "description": "Neo4j Bolt driver for Python",
+    "license": "Apache License, Version 2.0",
+    "long_description": open(path_join(dirname(__file__), "README.rst")).read(),
+    "author": "Neo Technology",
+    "author_email": "drivers@neo4j.com",
+    "keywords": "neo4j graph database",
+    "url": "https://github.com/neo4j/neo4j-python-driver",
+    "classifiers": classifiers,
+    "packages": packages,
+    "ext_modules": ext_modules,
+}
 
-# Used for reading the README into long_description below.
-def read(fname):
-    return open(os.path.join(os.path.dirname(__file__), fname)).read()
-
-
-setup(name="neo4j-driver",
-      version=version,
-      description="Neo4j Bolt driver for Python",
-      license="Apache License, Version 2.0",
-      long_description=read("README.rst"),
-      author="Neo Technology",
-      author_email="drivers@neo4j.com",
-      keywords="neo4j graph database",
-      url="https://github.com/neo4j/neo4j-python-driver",
-      classifiers=[
-          "Intended Audience :: Developers",
-          "License :: OSI Approved :: Apache Software License",
-          "Operating System :: OS Independent",
-          "Topic :: Database",
-          "Topic :: Software Development",
-          "Programming Language :: Python :: 2.7",
-          "Programming Language :: Python :: 3.4",
-          "Programming Language :: Python :: 3.5",
-          "Programming Language :: Python :: 3.6",
-      ],
-      packages=["neo4j", "neo4j.bolt", "neo4j.compat", "neo4j.packstream", "neo4j.v1"],
-      ext_modules=ext_modules)
+try:
+    setup(**setup_args)
+except SystemExit:
+    print("Compilation failed, falling back to pure Python.")
+    del setup_args["ext_modules"]
+    setup(**setup_args)